The present day forms of creating power are generally dependent upon the burning of fossil fuels to generate electric power. In doing so, a serious environmental problem is created in the form of air, water and land pollution. Also, in burning such fuels to create kinetic energy, thermal efficiencies are relatively inefficient due to the formation of incomplete combustion products. This results in exhaust pollution of these products, such as carbon monoxide, carbon dioxide, nitrous oxides and particulates.
Certain attempts have been made to create power without generating such pollutants. Williams U.S. Pat. Nos. 4,086,772 and 4,170,116 disclose a continuous method and closed cycle system for converting thermal energy into mechanical energy. This system comprises vaporizing means, including an energy conversion tube having a special nozzle section, for converting a liquid working fluid stream to a vapor stream. This vapor stream operates a turbine means wherein a portion of the energy of the vapor stream is converted to mechanical shaft work. This system also includes means for increasing the thermal and static energy content of the fluid stream, this means typically being pump means. The vapor fraction of that exits the turbine means passes through condensing means, such as a diffuser, to regenerate the working liquid stream. Finally, means are provided for recycling the condensed liquid stream back to the vaporizing means. The working fluid may be carbon dioxide, liquid nitrogen, or a fluorocarbon. Preferred fluorocarbons are difluoromonochloromethane, pentafluoromonochloroethane, difluorodichloromethane and mixtures and azeotropes thereof.
Johnston U.S. Pat. Nos. 4,805,410 and 4,698,973 disclose closed loop systems that recirculate a vaporizable working fluid between its liquid and vapor states in a thermodynamic working cycle. In this cycle, energy received from an external energy source is utilized to vaporize the fluid to a high pressure in a boiler unit. The resulting vapor is utilized in an energy utilizing device, such as a slidable piston which causes rotation of a crank shaft coupled to a flywheel to deliver mechanical output at a rotating shaft connected thereto. Thereafter, the vapor is condensed into a condensate at a relatively lower pressure in a condensing unit and then is returned to the boiler unit for repeating of the thermodynamic cycle. Also, the condensate flow between the condensing unit and boiler unit is collected in one of two holding tanks in selective pressure communication with the boiler unit. Preferred working fluids include water, Freon or ammonia. Also, thermal regeneration means may be included for providing regenerative heating of the working fluid.
U.S. Pat. Nos. 6,397,600 and 6,594,997, which are incorporated by reference herein, disclose a method and apparatus for efficiently generating mechanical or electrical energy. The method includes the steps of heating a vaporizable, first liquid heat transfer medium to generate a high pressure vapor; utilizing the high pressure vapor to provide mechanical energy and thereafter condensing the vapor to a liquid; and recycling the condensed liquid to the heating step for re-use as the first liquid heat transfer medium. The apparatus includes a closed loop heat transfer medium system having a first heat exchanger for heating a vaporizable, first liquid heat transfer medium to generate a high pressure vapor; a mechanical device which utilizes the high pressure vapor to provide mechanical energy; a condenser for condensing the vapor to a liquid; and piping for fluidly connecting the first heat exchanger, mechanical device and condenser, and for recycling the condensed liquid to the first heat exchanger for re-use. The first heat transfer medium is preferably maintained in a hermetically sealed circuit so that essentially no loss of heat transfer medium occurs during the heating and condensing steps, and is a fluorocarbon or fluorocarbon mixture that (a) generates a high pressure of at least 400 PSI at a pressure generation temperature that is below the boiling point of water, (b) has a boiling point which is below the freezing point of water, and (c) has a critical temperature which is above that of the pressure generation temperature.
While these prior art systems are somewhat suitable for their intended purpose, there remains a need for improvements in systems and processes for power generation, in particular for small, more efficient systems that operate at relatively low temperatures and that include engines for generating torque and power.